Hydraulic pump of the radial cylinder type



may as, 1946.

w; c. HOLDEN ETAL A 2,404,175 HYDRAULIC UMP OF THE RADIAL CYLINDER TYPEA Filedoct. s, m43 e sheets-sheet 1 @Kaw @www y A itorney n venlors E HOLD EN a xmms 6 Sheets-Sheef 2 July 16, 1946. w.l c. HQLDLENETAL HYDRAULIC PUMP OF THE RADIAL' .CYLINDER TYPE ,Filed oct'. s, 194s All cu LA n u' JomufxwHAU-m B4 v A www s vJuly 16,l l1946. w. c. HOLDEN ErAL 2,404,175

HYDRAULIC PUMP oF THE RADIAL CYLINDER TYPE Filed Oct. 8, 1943 6 Sheets-Sheet 3 mi a 5 w'/ f Q. g l :I o, ha

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HYDRAULIC PUMP 0F THE RADIAL CYLINDER TYPE Filed Oct. 8, 1943 6 Sheets-Sheet 5 1n m fu Q Arme/VFY July 16,'1946.

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A Trae/Vex Patented July 16, 1946 PUMP F THE RADIAL f CYLINDER Holden and Joshua Challiner HYDRAULIC Warwick Claude FFI CE TYPE l Naylor, Monkseaton, England, assignors to Vickers-Armstrongs Limited, London, England, a company of Great Britain Application october s, 1943, serial No. ,505,491

`In Great Britain June 25,

7 Claims. (Cl. ID3-38) This invention relates to hydraulic pumps of?" ythe kind which include a series of cylinders and ypari; of the pump pump at the deli 2 casing, the boring in the oatpermanent connection witha plate leading to the fluid in the therefore in pering ram being in passage .or passages in the cover the delivery side of the pump, ery side being fluid at the delivery side of the pump.

Without circulation of the pressure fluid, the pump rbeing virtually in a vstalled condition, the fluid circulated bythe rotor in such a case passing via the pump casing to the fluid head tank,

tem is kept at a uniform temperature:

The invention further resides -in 'providing a compact construction of pump having a minimum of rotating parts, permittingextens'ive'use oflight alloys and consequently the'formation of apump which is light in Weight.

In order that `the said invention maybe clearly understood. and `readily carried into `eiect Athe same will now be more fully described With'reference to the accompanying drawings ywherein:`

Figure 1 is a longitudinal vertical section'of an hydraulic pump constructed in accordance Iwith the invention. Y

Figure 2 is a transverse fragmentary section taken through the cylinder assembly and variable stroke eccentric.

Figure 3 is a sectional plan view illustrating the construction of the mechanism employed in Figures 1 and 2 for the eccentric,

'Figure 4 is a longitudinal vvertical section illustrating an alternative form of hydraulic pump.

Figure 5 is va transverse fragmentary section taken through Athe cylinder assembly and eccentric. l

Figure 6 is a sectional View of the eccentric and "spring saddle incorporated in the pump illus*- trated by Figures 4 and 5.

Figure 7 is a longitudinal vertical section illustrating a further modied form of pump.V Y

lFigure 8 is a transverse section thereof r.through the cylinder assembly and its eccentric.

Figure 9 is a sectional viewzillustrating the 'construction of the operating mechanism for varying the eifective stroke of the eccentric and/0r presvarying the effective stroke of pipe.

.ders formed `on the part I.

radially tofforrn anumber of radially'arranged 5 cylinders in each ofrwhich cylinders isslidably mounted a piston 2, each cylinder being closed., at its outer end by means of a cover plate 3, outward movement of the pistons within their assoeiated cylinders being controlled by an eccentric 101 y a liquid seal between the two parts 59 and 5I.

` The valve above described operates in such a 1 manner that when liquid pressure is exerted from outside the valve it will act on the part 59 and f of variable stroke carried by a driving, shaft. The

driving shaft 4 is rotatably mounted within bearings 5 in a distance piece 6 which is bolted to the pump body at one end, the shaft being rotatably/g mounted at its opposite endwithin bearings 1 15 tact with the sealing face 55.

2in the pump body, the shaft being extended be-v yond the bearings to carry a rotor 8 for 'the-pur-Y pose of maintaining fluid circulation when the j pump is maintaining pressure in the delivery pipe f ,line without circulation 'of the pressure fluid, the 20 pump being virtually ina stalled position, i. e. I idling, so asv not to produce the pressure required to 'drive the apparatus when it is operating from I the pump the fluid circulated by the rotor in such a casepassing via the pump casing to the fluid 2,5

head tank, the fluid thence returning via the inlet 'The valve 9 Loperates within a recess formed... in a cover plate I0 which is bolted to the pump `35 the cylinders under thel control of the eccen- 40 trically actuated 'valve takes place by way of the common fluid inlet and discharge passages I3,l .which'le'ad to the respective cylinders.

Y The said .valve comprises two concentric parts and `5I the outer of which,l 5I, is freelyl'our- 45 Vnalled on the inner and is driven therefrom by means of a driving pin 52 mounted in the part 50 and adapted to engage between a pair of shoul- The inner, part 50 is mounted in anysuitable manner on an eccentric member 53 which is associated with Ythe shaft, and by virtue of such eccentricity the whole valve Vis caused on rotation of the shaft to move in an eccentric path over sealing faces 55 and 56 formed on the outer end of a cylinder block or barrel 55 and on the inner surface of the endV cover I0. v

The inner part 5011s formed with an voperative Aface 59,0f annular form opposed to the cylinder block which is adapted to control a ring of ports y Y such as 60 forming the outer termini of the pas-V 60 sages I3, which are arranged in the sealingv face 55 at a constant radius'from the centre of the shaft while rthe outer part 5I is also provided with an operative face 6I adapted to slide over the inner face 56 of the end cover .I I. axially. directed springs such as 62 are interposed between the two parts 50 and 5I in known manner to cause the operative faces 59 and 6I to bear against their respective sealing faces during those periods when the liquid pressure falls below a predetermined value while a suitable sealing device is also provided Vbetween the periphery of the inner part 50and the outer part 5|, in ordento prevent leakage of liquid between said parts. In

This circulation ensuresthat the fluid in y l the system is kept at a uniform temperature.

` The flow of oil or other fluid to and from the, 1 pistons is controlled by an eccentrically actuatedv 30 3 valve 9, such as, for example, the self sealing type of valve forming the subject of British Patent A plurality of 05 comprises a ring 63 of flexible material which is of substantially U-shape in cross section and is disposed in a recess 64 formed between the parts 50 and 5I. Also located on the part 50 and adapted to co-operate with the ring 63 is a second ring 65 whichmay be formed ofY brass or other suitable material' and provided with suitable conduits, channels or the like adapted to allow the pressure of liquid outside the valve to act on the ring 63 and cause the same to expand to effect and drawings circo-pending patent application 'Nd 505,490, and engage seatings in slippers I4 which in turn engage the outer surface of an annular ring I5, the latter being rotatably mounted about the eccentric, needle type bearings I6 being interposed between the eccentric and the ring I5 with the object of reducing friction between the parts to a minimum l The eccentric I8 is slidably mounted upon the driving shaft ina direction at right angles to the'shafts axis, the shaft at the point I1 where the eccentric is mounted, thereon being of square or rectangular shape, which will provide two parallel plane surfaces over which the eccentric can slide.

To enable the eccentric I8 to be moved at right angles to the axis of the shaft with a minimum of friction, rollers 26 are provided which rollers are rotatably mounted upon pins 2l, the rollers making contact with the 'plane surfaces of the shaft... L V l r The eccentric I8 is maintained normally in its position of maximum eccentricity by a number,

for example four, helical springs 23 located within A hollow ram 25 (see particularly Figure 1) is slidably mounted within a radial boring in the shaft,` the lower end of the ram contacting, the inner surface of the eccentric I3. The ram is bored axially as at 26 and is bored radially as at 21, the radial borings communicating with lthe laxial boring 26, the ram being also formed with a peripheral groove28 which communicates with the radial borings 21.

The boring 26 in the ram is connected with the delivery side 'of the pump by wayy of an axial .boring 29 in a floating ram 30 slidably mounted within an axial boring in the driving shaft 4. The floating ram 30 is spherically seated into a face member 3l. driven by the shaft 4 and so proportioned to maintain a runningpressure seal at the sealing face of the stationary cover plate I0 and is sealedby the pressure exerted by the viluid on the inner end of the. floating ram, a coil spring 32 being associated with the floating ram 30for maintaining contact of the, face member 3I with the sealing face on the adjacent surface of the cover plate when the iiuid pressure is below that exerted` by the sprmg. The boring in the oating ram 30 is in permanent connection with the embodiment illustrated thev sealing device a passage 33 in the cover plate leading to the ITB \ livery fpassage -|2rofthe vpump,"ftl:re a'xtalfboring fin thefsha'ft fortlre receptionfofthe{nating'ram itight connection. v

"The arrangmen't of the pump i's-fgenerally ilsmto'thatdisclosed byFigures 'I1-i3 and furthat reascn I'similar reference "numerals are -femp'loye'd to indicate similaror substantiallyfsimilarparts.

-by aring |811forming the 'eccentric lare k:separated from Tthe 'l ensure that the pin and piston 'nected together 'during'fthe @inward istrke -of inthe Jpistrms.

The pins '39 resi-,sin "arcuate shaped seatings formed in slippers f4 which 2in Y.turn Vengage*the lperipheralfsurface r4fof wa ring I5 surrounding the "access by'way of an axialbyorn'g in the driving shaft and a'hollow Heating ram `such as that illustrated n'fFigure 1. The arrangementis "such of the pistons in an outward direction.

In each construction illustrated the sldable eccentric is held at axis of the shaft, this no-delivery position, livered by the pump l the pressure of l Patent of the United States is: having a series of j cylinders and a common driving shaft an responsive to the influence of Y common driving lnection with the pistons the quantity of iiuid debeing thus determined by fluid at the delivery side.

of the eccentric and, therefore,

the effective stroke of the pistons, is of course .dependent on the fluid pressure at the delivery side. Such a construction of pump as is hereinbevirtue of construction Vris particularly suitable for use on aircraft and for dealing with extremely light r freezing oils, and is capable l speeds.

antiof high rotational What we claim and desire to secure byLetters l. In a hydraulic pump pistons radially arranged around y eccentric in operative engagement with the shaft and in driving connection with the pistons and means which is the fluid pressureV in the dischargeside of the pump for varying the degree of eccentricity of the eccentric and effec..`

tive length of stroke of the pistons; the provision of opposed plane surfaces on the shaftand eccentric respectively, anti-friction means-located between said plane surfaces, and means accom-` the shaft for transmitting fluid modated within pressure to said eccentric to cause same to move at right angles relative to the axis of said shaft.

2. In a hydraulic pump having a series of position corresponding-t a its light and compact Y passing axially cylinders and pistons radially arranged around a Y shaft an eccentric in operative engagement with the shaft and in driving connection with the vpistons and means which is responsive-to the innuence Vof tlie-fluidpressure in the discharge side of the'pump for varying thedegree of eccentricity of the eccentric-and effective length of stroke of the pistons; the provision of opposed plane surfaces on the shaft and eccentric respectively, anti-friction means located between said plane surfaces, and a fluid actuated ram for varying 'the degree of eccentricity of the eccentric, said ram being located the shaft and movable in a direction at right angles to the axis of the sha-ft.

3. In a' hydraulic pump having al series of cylinders and pistons radially arranged around a common driving shaft an ecce 4tric in operative engagement with the shaft and' in Adriving conand Ymeans which is responsive to the influence of the uid pressure in the discharge side of the pump for'varying within a boring in the degree of eccentricityV of the-.eccentric'and effective length of stroke of the pistons; the provision of opposedV plane surfaces on the shaft and eccentric respectively, anti-friction means located betweenV said plane surfaces, and a fluid actuated ram for varying the degree of eccentricity of the eccentric, said ram being located within a boring indirection at right angles to the axis ofthe shaft and means permanently connecting said ram with the delivery side of the pump. f p 4. In a hydraulic pump having a series of cylinders and pistons radially arranged around av common driving shaft an eccentric in operative engagement with the shaft and in driving connection with the pistonsy and means which 'is responsive tothe influence of the fluid-pressure in the -discharge side of thepump for varying the degree of eccentricity of the eccentric and effective length of stroke ofthe pistons; the provision of opposed planeA surfaces on the shaft and eccentric respectively, anti-friction means located between said!y plane surfaces, and a fluid actuated ram for varying the degree of eccentricity of the eccentric, said ram being located withinA a boring in direction at right angles to the axis of the shaft a radial boring in the shaft, a hollow ram slidable in said boring with its lower end contacting the inner surface of through the shaft and communicably connecting the interior of said hollow ram with the delivery side of the pump. f c

5. A hydraulic pump as claimed in claim 1 wherein the anti-friction means comprise rollers mounted on pins, and contactingrthe plane surfacesoftheshaft.' -Y n 6. A hydraulic' pump as claimed in claim 1 wherein the plane surfaces of the eccentric are formed by segmental blocks carried bythe ecycentric and are separated Vfrom the plane surfacesof the shaft by needle-type bearings located within slots in a cage. l'

7. A hydraulic pump as claimed in' claim 4 wherein said hllow ram. has an axially arranged and surrounding annular groove connected with said axial boring .by radially arranged borings, and an axial passageway through the shaft connecting said annular groove with the delivery side of the pump.

WARWICK yCLAUDE HOLDEN. n JOSHUA CHALLINER NAYLOR.

the shaft and movable in a the eccentric and -meansV 

